In the field of liquid crystal display (LCD) technology, a voltage buffer (VB) and a source driver (S-IC) are two separate and distinct ICs. Generally, when attempting to adjust a gamma reference voltage on a display panel, the gamma reference voltage is provided by the voltage buffer IC (integrated circuit) to the source driver IC.
FIG. 1 is a block diagram illustrating a programmable voltage buffer and a source driver in conventional art. Referring to FIG. 1, a timing controller 110 is coupled to a plurality of source drivers 110_1, 100_2 to 100_N. A pixel data 102 is transmitted correspondingly from the timing controller 110 to each of the source drivers 100_1 to 100_N via a data bus 104. The voltage buffer VB may provide a gamma reference voltage 106 to the source drivers 100_1 to 100_N. The source drivers 100_1 to 100_N receives the gamma reference voltage 106 to generate a drive voltage 108 to a display panel 150.
However, when a liquid crystal display is displaying an image, a frequent changes of characteristics of the reference voltage 106 (i.e. changing of gamma curve) is required to optimize display quality of the image. In some cases, different gamma curves are even required in different portions of the same frame for displaying specific images. In view of the FIG. 1, all of the source drivers 100_1 to 100_N in conventional art receive the same gamma reference voltage provided by an external voltage buffer VB, it is obvious that the conventional source driver does not meet the requirements as mentioned above.